Five Times Sherlock Listened to John's Heartbeat
by thirdbird
Summary: Sherlock is obsessed with John's heartbeat. John/Sherlock developing romance, mature but not explicit. (Originally published January 2011.)


_1. Trauma_

Sherlock shifts restlessly on the hard plastic hospital chair, his arse numb from sitting for so long. He hardly registers the discomfort; his whole being is attuned to the monitor and its soft, implacable, barely-audible _blip. blip. blip. blip. blip._ He's been watching it for hours, mesmerised, afraid to tune it out or shut his eyes for fear that if he stops willing it to keep on, the evidence of John's continuing stubborn determination to exist will simply wink out.

Six words echo in an endless loop through his head while he watches the blips: _burn the heart out of you, burn the heart out of you, burn the heart out of you._

_2. Examination_

John's got his medical kit out on the bed. Usually it's all neatly packed and stowed with military precision, but today there's a messy sprawl of instruments strewn across the spread, right next to where Sherlock's perched while John patiently digs splinters of shattered glass from his upper back and drops them into a curved metal dish.

"Worse than shrapnel," he complains. "Harder to see."

John's voice continues to hector and fret as he works, providing a comfortable balm of white noise against the sharp spikes of pain. Head bowed in a sham display of penitence, Sherlock finds himself staring at the panoply of medical supplies spread out before him. He picks up the stethoscope, fits it to his ears, blows experimentally into the chestpiece before resting it against his own ribs. It's a cacophony of noise in there. He clears his throat and jumps at the sound it makes.

"Put it down," John tells him, finishing up with the tweezers and applying antiseptic ointment. "It's not a toy."

Sherlock ignores him and continues to listen to himself, moving the chestpiece here and there. He can't see how John, or anyone, is able to glean any useful information from this collection of random-seeming sounds, but then living bodies have never been his specialty.

"Done," John announces. "Can you-"

"Quiet a minute." Sherlock stands up and turns the stethoscope on John. He listens for a moment, then plucks at John's jumper. "Take this off, I can't hear anything but wool."

John rolls his eyes and gives one of his long-suffering _my flatmate is a maniac_ sighs, but he's used to all manner of odd commands by now. He sheds his jumper and allows himself to be auscultated.

It's quieter in John's chest cavity than it is in Sherlock's, it seems, but that could be partly due to the muffling effect of the remaining thin barrier of cloth. Sherlock considers asking John to remove his shirt, too, but that would probably be an untoward request. He can hear well enough, anyway. He listens, rapt, until John's had enough and reaches up to take the instrument away from him.

"What's your diagnosis, then?" he asks Sherlock, amused despite himself. "Am I fit for duty?"

"Haven't got a clue," Sherlock admits. "It's merely noise to me. I just like the way you sound."

_3. Chase_

They've been running, and now they're hiding, because those rare book thieves they were pursuing turned out to be considerably more well-armed than mere bibliophiles have any right to be. The cupboard Sherlock yanked John into is small, and nearly airless, and they're not exactly squashed together but it's nearer than they usually get, near enough for Sherlock to smell John's shampoo and the faint tang of his sweat. Near enough to see the tiny throb of his pulse, trapped and surging beneath the skin of his throat.

There are footsteps right outside. They hold their breaths. John's eyelids fall closed.

Then the footsteps move on.

They both sag a little with relief, but they don't move right away, not until they hear the faraway shout of arguing voices two floors down, and the heavy thud of the building door. Even then Sherlock stays John with a hand on his arm, making them wait for another full minute before cautiously opening the cupboard door.

John takes a step out and then collapses to the floor, his feet getting tangled with Sherlock's, bringing him down as well. The air tastes unimaginably cool and sweet, and John is laughing.

"I thought my heart was going to explode. Literally. Explode. Feel that," he says, and grabs Sherlock's hand, pressing it to his chest.

Sherlock goes still, feeling John's heart race. Inches beneath his hand, a fist-sized muscle is pumping oxygenated blood through John's body in response to an increase of adrenalin in his system. Nerve receptors in Sherlock's skin are allowing him to perceive the vibrations caused by this phenomenon. This perfectly ordinary biological occurrence.

The strange sensation it's causing in the pit of Sherlock's stomach is a perfectly ordinary biological response as well, no doubt, but he doesn't wish to think about that right now. If it he ignores it, he tells himself, it will go away.

He doesn't move, though. He keeps his hand on John's chest until his breathing slows and the pounding lessens, keeps it there while John turns his head and gives Sherlock an open, curious, considering look.

The heartbeat begins to pick up speed again.

_4. Experiment_

The sofa in their flat is made for kissing, it turns out; Sherlock has no idea why he'd never noticed it before. No, scratch that, _John_ is made for kissing, and the sofa is a convenient and useful setting for that activity. He's kissed John on that sofa eleven times now, about to be twelve. He's starting to get an erection just from looking at the thing.

Time number twelve is going along swimmingly. Sherlock is straddling John's lap, arms braced against the sofa back on either side of John's head, and the kissing has gone from slow and gentle to deep and exploratory. John's shirt is unbuttoned and he's breathless, urgent, his hips starting to cant up towards him a little so that Sherlock can feel just how aroused he's becoming...and that's when Sherlock breaks it off (John makes the sweetest little sound of high-pitched involuntary protest) and says, hopefully, "Can I?"

John looks wild-eyed and uncomprehending for a moment, and then his head falls back against the wall with a small clunk. "You want to, with the-now? Yes, right, of course now, that was the point. All right," he sighs, and Sherlock hops up.

"I'll get it," he says happily. "It's still in the bathroom from the pre- and post-shower trial I ran this morning."

Sherlock is conducting an informal study: _Blood pressure changes in response to environmental and social stimuli: Subject, JHW, 39-year-old male. _In theory it could be useful for a case, someday, somehow, Sherlock supposes. In actuality, he loves to study John, and this is the best way he's found yet of quantifying him.

He returns to the living room, sphygmomanometer in hand. John taught him how to take a reading, an act which he claims now to regret, but he hasn't once refused when Sherlock asks if he can do it again. He's got his sleeve rolled up now, ready and waiting. Sherlock fixes the cuff into place around John's upper arm and kisses him a few more times for good measure before inflating it and sliding the stethoscope up against the brachial artery. He's reverent, listening to the sound of John's blood rushing through the tiny channels inside his body.

"One-eighty-five over ninety-five," Sherlock reports. "That's brilliant, that's the highest reading yet." _I did that to him,_ he thinks with infinite satisfaction. _Me. The Sherlock Effect._

John gives his shoulder a playful shove. "I'm exhibiting classic signs of acute hypertension, and you're grinning like a kid on Christmas morning. What's wrong with this picture?"

"Absolutely nothing," Sherlock says smugly. "You're in gorgeous health, and you know it." He's still got the stethoscope in his ears, and he can't resist the temptation to push up John's vest and press the chestpiece against bare skin as he leans in to kiss him again, and again, all of his senses drowning in John, inside and out. It's the next best thing to being able to crawl inside John's body and live there. "I want to know what your heart sounds like while you're having an orgasm," he murmurs, and John groans.

"Only you could make a proposition like that sound sexy," John says faintly, and just like that he's going to let him do it, Sherlock realises with awe. John's going to let him do everything to him from now on, forever.

It's _exactly_ like Christmas morning.

5 +1. Nightmare / Tin Man

It doesn't happen often anymore, but when it does it's always shattering for both of them, John because he thinks he should be over it by now and Sherlock because he doesn't know what to _do._ If Sherlock happens to be in bed with him when it starts, he can sometimes head it off, wake him up-he's become very good at reading the signs of an incipient nightmare, and sometimes the warmth of his body and the murmur of his voice is enough to nudge John's sleeping mind off the blood-and-bone-paved path that leads to the battleground.

Sometimes, though, it's not enough. And sometimes, like tonight, Sherlock's still downstairs working on four experiments at once, blissfully oblivious to the rest of the world, until the sound of shouting from the upstairs bedroom alerts him.

John's awake by the time Sherlock can get up to his room, and that's good. When he's in the full grip of a nightmare, it's very difficult to wake him without getting hurt, and John has warned Sherlock not to try. He always tries anyway, of course. The last time ended in bloodstains all over the sheets and the rug and his favourite blue dressing gown, and John having to set his broken nose in the bathroom at two in the morning. ("I'd do it again, I don't care," Sherlock had said afterwards, stubbornly if somewhat nasally. "Better this than having to just watch and know that you're in hell somewhere in there." "Not better for _me,_" John told him, and Sherlock didn't know what to say to that.)

So he's awake this time: good. But his arm is over his eyes and his shoulders are rigid in that particular way that means he's holding himself together through sheer force of will, and Sherlock has a terrible feeling John is wishing he'd go away so he could fall apart in private.

There's no right answer. Sherlock hates this. He's as terrible at relationships as he's ever been. It's always the same, no matter how brilliant the sex part is, there's always things like this and he always, always fails.

But it's John, so he has to try, even if he gets it wrong again. He climbs under the covers and nestles up to John without saying anything, puts his cold bare feet against John's warm ones and his ear against John's chest. His heart is still beating panic-fast. Sherlock raises his head after a minute and says "Can I-"

"No, you bloody well can't," John snaps out. "I'm not in the mood to be one of your _fucking_ science experiments right now. Christ, Sherlock."

He sounds so disgusted that it's hard not to react-physically difficult, Sherlock notes, not to bite back with words that will sting, or to get up and remove himself from the situation, escape, retreat back to a place where he can live on cold and clean deductions and not all these messy, blood-temperature feelings.

He waits, instead, until he can speak in a calm and measured voice. "I was going to say, can I get you anything. Water? Tea?"

"Oh." John's voice is small. "I- No. Nothing. Sorry," he adds grudgingly. "I should've known you wouldn't, that you didn't mean- Sorry."

And now he's put John in the wrong, which is terrible again. Especially because Sherlock _would_. He wasn't going to suggest it, not this time, but that's only because he still remembers the row that ensued that time when he'd asked if he could take John's blood pressure after he'd got off the phone with his sister. He'd thought it might defuse the tension, get John's mind off it-and, all right, he'd been curious. It's how Sherlock's mind works, it's what he does.

So he'd been congratulating himself a bit, just now, on having the sense not to actually ask, to content himself with surreptitiously counting John's pulse rate instead, and now John's thinking_ he's_ the monstrously insensitive one, which is unacceptable. He starts to say something, but John speaks first.

"Hey," he says, giving Sherlock a little dig in the side with his elbow. "Why're you so obsessed with my heartbeat all the time, anyway, do you suppose? Hm?" His voice is fond again, still a little rough but determined to steer them back onto lighter ground.

Sherlock thinks about it. "Because I haven't got one of my own?" he jokes.

"Tin man," John says, and knocks on Sherlock's chest. "Right. And that makes me the scarecrow, I suppose. Cultural reference," he explains, when Sherlock looks blank. "_The Wizard of Oz._ Musical film from the late nineteen-thirties. Judy Garland? 'Somewhere Over the Rainbow'? I'm not about to humiliate myself by attempting to sing, but you've heard it, trust me."

"I know _The Wizard of Oz_," Sherlock informs him. "It's your comparison I don't understand. You've got a brain."

"And you've got a heart. Look, I'll prove it." He gets up and fetches his stethoscope from the dresser top. Sherlock tries not to roll his eyes. John really can be extraordinarily sappy sometimes, he thinks.

When John places the instrument against Sherlock's chest, though, a fleeting expression of concern crosses his face-quickly schooled, but his eyes dart to Sherlock's and then away, and he continues to listen intently.

"What?" Sherlock demands, because that's really not a look you want to see on a doctor's face. His mind skitters over various horrible possibilities. "John? What?"

"Nothing," John says. "Shut up a minute. Breathe?" He moves the chestpiece. "Again? Huh. No, it's...I can't believe this, actually, but you were right, you have no heart. There's nothing in here, it's completely empty."

He's so utterly deadpan that it takes Sherlock a minute. "Oh, for God's sake." He gives a disbelieving laugh. "You're _ridiculous_."

"Wait, no, hang on, there it is," John says, still listening. "_Racing_, actually. Oh, very nice. Scare you a bit, did I?"

"No," Sherlock says indignantly, but the evidence against him is incontrovertible, unfortunately, and in the end he decides that the only way to save face is to initiate a wrestling/tickling match.

He never does make it back downstairs that night, and at least two experiments are hopelessly ruined, and nothing's been resolved at all. Perhaps it never will be; perhaps it can only be deflected.

Even so, it's a better ending to the evening than he'd anticipated.


End file.
